package pro.cherish.knowledgeutil.common;



import lombok.extern.slf4j.Slf4j;
import pro.cherish.knowledgeutil.str.StringUtilExt;


import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * IP地址
 * 
 */
@Slf4j
public class IPUtils {

	/**
	 * 获取IP地址
	 * 
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr(HttpServletRequest request) {
    	String ip = null;
        try {
            ip = request.getHeader("x-forwarded-for");
            if (StringUtilExt.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (StringUtilExt.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (StringUtilExt.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (StringUtilExt.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            if (StringUtilExt.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
                if (ip.equals("127.0.0.1")) {
                    // 根据网卡取本机配置的IP
                	InetAddress inet = null;
                    try {
                        inet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        throw e;
                    }
                    ip = inet.getHostAddress();
                }
            }
            // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            // "***.***.***.***".length()// = 15
            if (ip != null && ip.length() > 15) { 
                if (ip.indexOf(",") > 0) {
                	ip = ip.substring(0, ip.indexOf(","));
                }
            }
        } catch (Exception e) {
        	log.error("IPUtils ERROR ", e);
        }
        
        return ip;
    }

}
